Petals distinct; stamens perigynous or epigy-nous.

Order 21. Aquifoliaceae. - Shrub, evergreen; leaves spinose, leathery; stipules small, falling; flower regular, unisexual, in cyme, axillary; sepals 4-5, inferior, overlapping; petals 4-8, united below; stamens 4-5, adnate to petals; disk absent; ovary syncarpous, free, 4-locular; ovules solitary; fruit a drupe with four stones, fleshy; seeds stony 2-6.

Order 22. Celastraceae. - Shrub; stipules very small, falling; flowers regular, in cyme, axillary; sepals 4-5, overlapping; petals 4-5 on margin of fleshy disk; stamens alternating with the petals; ovary syncarpous, 3-5-locular; cells 1-2-seeded; ovules erect; fruit a fleshy capsule; seeds enclosed in aril.

Order 23. Rhamnaceae. - Shrubs, deciduous; leaves alternate; stipules minute; flowers regular, small; sepals 4-5; valvate in bud; petals 4-5, distinct, on throat of calyx; stamens 4-5, epipetalous; ovary syncarpous, 3-locular, generally superior; fruit a drupe; seeds erect, 2-4.

Order 24. Aceraceae. - Trees, deciduous; leaves opposite; no stipules; flowers regular, in raceme or corymb; sepals 4-9, overlapping; petals 4-9, on hypogynous disk; stamens 8, on disk; style 1; stigmas 2; ovary syncarpous, 2-lobed; 2-locular; ovules 2 in each cell; fruit a schizocarp; mericarps (samaras) 2, winged, 1-celled, 1-2-seeded.

Order 25. Leguminosae. - Herbaceous plants, or shrubs, some evergreen; leaves alternate, compound; stipules to leaves and leaflets; flowers irregular, papilionaceous; calyx inferior; sepals 5, combined, 1 anterior; petals 5, odd one posterior; stamens in 1 bundle of 10 or 2 bundles of 9 and 1; ovary I-celled, free; fruit a legume; placenta on upper suture.

Order 26. Rosaceae. - Herbaceous plants, shrubs, trees (deciduous); leaves alternate, simple or compound; with stipules; flowers regular, perigynous as a rule; sepals 4-5 or 8-10 in 2 rows, free or adhering to and enclosing the ovary, odd one posterior; petals 4-5, equal, perigynous; stamens indefinite, perigynous; styles distinct, often lateral; carpels 1-4, or many, usually apocarpous; ovules 1-2 in each; fruit an achene, drupe, pome, etc.; seeds mainly without albumen.

Order 27. Saxifragaceae. - Herbaceous plants, or shrubs (deciduous); no stipules; flowers regular, epigynous or perigynous; sepals 4-5; petals 4-5 or none; stamens 5 or 10, free, perigynous or hypo-gynous; styles 2, free, diverging, persistent; ovary superior or inferior; I-locular, with placentae 2, parietal, or 2-locular with axile placentae; fruit a capsule, or berry; seeds many, with fleshy albumen.

Order 28. Crassulaceae. - Herbaceous plants; stem fleshy; leaves fleshy, tufted; no stipules; flowers regular, slightly perigynous; sepals 4-12, united below; petals 4-12, sometimes united, inserted at base of calyx; stamens 8-24, sometimes epipetalous; carpels 5, opposite the petals, free as a rule, 1 -celled; fruit aggregate, follicle; seeds with some albumen.

Order 29. Droseraceae. - Herbaceous rosette-plants; leaves insectivorous, glandular, with circinate vernation; flowers regular; sepals 5, overlapping; petals 5; stamens 5, hypogynous or perigynous, free; styles 3 or 5; ovary free, syncarpous, 3-5 carpellary, I-locular; ovules many on 2-5 parietal placentae; fruit a capsule, 2-5-valved with seeds on margin of valves; seeds without an aril.

Order 30. Haloragaceae. - Aquatic plants, herbaceous; no stipules; flowers unisexual, apetal-ous; calyx adnate to ovary, limb minute; sepals 2-4 or none; stamens 8, 4, 2, or 1; styles equal to, or half as many as, cells; ovary inferior, I-car-pellary, or syncarpous and 4-locular; ovule 1 in each loculus; fruit dry, crowned with rim of calyx; seeds pendulous, with fleshy albumen.

Order 31. Lythraceae. - Herbaceous plants; no stipules; flowers regular; calyx tubular; sepals 4-6, valvate in bud; petals 4-6, between sepals, twisted in bud, falling; stamens 8-12, on tube of calyx, below petals; style 1; ovary superior, syncarpous, free, 2-celled; fruit a membranous capsule, 2-valved, I-celled; seeds many.

Order 32. Epilobiaceae vel Onagraceae. - Herbaceous plants; leaves alternate or opposite, not dotted; no stipules; flowers regular, epigynous; calyx tubular; sepals 2-4, valvate in bud; petals 2-4, twisted in bud, at top of tube; stamens 2-4, or 8, inserted with petals; style 1; stigma capitate; ovary inferior, syncarpous, 4-locular; placentae axile; fruit a capsule, many-seeded.

Order 33. Cucurbitaceae. - Herbaceous succulent tendril-climber; plant monoecious or dioecious; no stipules; calyx 5-partite, tube attached to ovary; corolla 5-partite, bell-shaped, with netted veins; stamens 3, cohering; anthers wavy; style short; stigmas lobed; ovary 3-5-celled; placentae parietal; fruit a berry; seeds flat, in an aril.

Order 34. Umbelliferae. - Herbaceous plants; leaves much divided, sheathed below; flowers regular, as a rule in a compound umbel; calyx 5-partite, teeth very small, or absent, adhering to the ovary; petals 5, turned inwards; stamens 5, inserted with petals; styles 2, disk fleshy; ovary 2-celled; fruit a schizocarp, of 2 mericarps, adhering by the commissure; seeds solitary, pendulous.

Order 35. Araliaceae vel Hederaceae. - Shrub, evergreen, root-climber; leaves alternate; stipules none; flowers regular, in simple umbels; sepals 5, adnate to ovary; petals 5, or wanting, valvate in bud; stamens 5, alternate with petals, inserted below disk (epigynous); styles 5; ovary inferior, 5-locular; fruit a drupe, with 5 stones, succulent or dry; seeds solitary, pendulous.

Order 36. Cornaceae. - Herbaceous plants, or shrubs; leaves opposite; stipules none; flowers regular; sepals 4-5, adnate to ovary; petals 4-5 inserted on top of calyx-tube, valvate in bud; stamens 4; style slender; ovary 2-celled; fruit a drupe, with 2 stones, crowned with remains of calyx; seed solitary.